.calculator{width:260px;height:240px;padding-left:5px;padding-top:5px;background-color: #333333;position:relative;}
.calculator .num_key{width:50px;height:45px;display:inline-block;background-color:#666666;margin:5px;line-height: 45px;text-align:center;font-size:18px;color:#FFFFFF;font-weight:bold;}
.calculator .btn_key{width:50px;height:45px;display:inline-block;background-color:#666666;margin:5px;line-height: 45px;text-align:center;font-size:18px;color:#FFFFFF;font-weight:bold;}
.calculator .num_key:hover{cursor: pointer;}
.calculator .num_key:active{cursor: pointer;opacity:0.7;filter:alpha(opacity=70);}
.calculator .btn_key:hover{cursor: pointer;}
.calculator .btn_key:active{cursor: pointer;opacity:0.7;filter:alpha(opacity=70);}
.calculator .ok{height:100px;line-height:100px;position:absolute;}
.calculator .zero{width:50px;}
.calculator .my_clear{width:50px;}